Push button device



June 8, 1965 R. G. COUSINS PUSH BUTTON DEVICE 2 Sheets-Sheet 1 Filed June 29, 1961 June .8, 1965 R. s. cousms 3,187,602

PUSH BUTTON DEVICE Filed June 29, 1961 2 Sheets-Sheet 2 Mrs/v70? AMWL W 0 United States Patent Ofilice 3,187,602 Patented June 8, 1965 3,187,602 PUSH BUTTON DEVICE Richard Geoffrey Cousins, Norwood, London, England,

assignor to Telephone Manufacturing Company Limited, London, England Filed June 29, 1961, Ser. No. 120,612 Claims priority, application Great Britain, July 6, 1960,

1 Claim. ((31. 74-483) This invention relates to push-button switches, more particularly to push-on/push-off, switches and to interlocking mutually releasing ganged push-button switches.

A push-button switch of the push-on/push-oif type, that is, a switch which is pushed once to operate the switch, the button remaining in the operated (On) position until it is pushed again to restore the button to its original unoperated (Ofi) position is known.

Demand has arisen for a switch of this type which may also be used as the basic switch in a ganged group of such switches in which the operation of any switch automatically releases any other switch that may have been previously operated. The arrangement of push-button switches in such ganged groups is well known in such applications as push-button tuned radio receivers, intercommunicating telephone instruments and other devices.

In the normal way, such a ganged group of switches is designed and constructed specifically with the one purpose of mutual release in mind; thus avoiding unnecessary complication and cost. The individual switches of the gang cannot usually be alternatively used as separate push-on/push-off switches.

It is the object of the invention to provide a simple switch unit which may be used either as a single pushon/push-off switch or may be ganged with similar switches to form a mutually releasing group of switches.

According to the present invention a push-button switch using the pin and track principle of operation is adapted to act either as a push-on/push-off switch or as a unit of a mutually-releasing gang of switches by the provision of one track for guiding the pin when the switch is used as a push-on/push-oif switch and a different track for guiding the pin when the switch is used in a mutually releasing gang of such switches.

The method of pin and track operation and the form of track preferred for use in a push-on/push-otf switch is fully described hereinafter. In the embodiment disclosed, one portion of a closed circuit track is used on operation of the switch and a second portion of the track is used on release of the switch. In the switch of the present invention a further track is added, this track being used for release when the switch is released by the operation of another switch of a gang of such switches.

The provision of this additional track adds virtually no cost to the switch since it is incorporated in a moulded track unit which, for convenience, may form part of a moulded push-button. The further addition of a resetting bar, common to all the switches in a gang of mutually restoring switches, is all that is necessary to convertthe switch from individual push-on/push-off operation to mutually releasing operation.

The invention will be described further by way of example with reference to the accompanying drawings, in which FIGURE 1 shows parts of a moulding with two separate tracks, 7

FIGURE 2 shows a section view of the pin and resetting bar used with separate tracks,

FIGURE 3 shows a combination of the two tracks,

FIGURE 4 shows the pin and resetting bar used with combined tracks,

FIGURE 5 shows three push buttons and the common resetting bar,

FIGURE 6 shows a section through a single push button switch incorporating the parts of FIGURES 1 and 2, and

FIGURE 7 shows a side view, partly cut away, of a gang of three of the switches of FIGURE 6 arranged for mutual releasing operation.

Referring to FIG. 1 for simplicity of illustration the track is shown as though cut out of a rectangular block and with the right hand wall cut away but in practice it forms part of the push button moulding. The track which has a heart-shaped configuration comprises a groove 50 surrounding a V-shaped central portion or island 51. The track is symmetrical about this island but in order to show the detail of the walls of the groove the right hand portion of the block from the top edge of the groove to the bottom edge of the front face of the block is shown cut away in extension of the surface of the base of the groove. The position of the foot of the wall omitted in this way is indicated by a dotted line. The left hand arm a and the top V-shaped portion b of the groove forming the track 59 are of the same depth but the right hand arm 0 is of progressively increasing depth from its junction with portion b to its junction with arm a so as to form a ramp terminating in a step d at the junction of a and c.

The normal rest position of the pin which operates in this track, which pin is indicated in dotted line in FIG- URE 2, is below the junction between arms a and c and abutting the face 3 under'the effect of a load spring urging it in that direction. Upon movement of the track member relative to the pin in the direction of the arrow the pin is guided to travel up the ramp arm c against the bias of its load spring until it reaches the junction e between track portions b and 0. At this point the load spring urges the pin into track portion b to abut against the wall 7. Upon reversal of the direction of movement of the track the pin rides along wall 1 to lodge in the angle g of the V portion b where it locks the track member against any further movement in the reversed direction.

When the track member is again moved in its original direction the bias of the load spring causes the pin to ride along the wall h of track portion b until it reaches the junction between track portions a and b. Reversal of movement of the track member at this point causes the pin to ride along arm a until it falls down the step d and moves into its normal rest position.

The track just described is used in combination with a pin in the dotted line position indicated in FIGURE 2 of the accompanying drawings when the switch in which it is incorporated is required to act as an individual pushon/push-oif switch, the track moulding forming part of the push button which also serves to actuate contact assemblies as will be later described.

When a switch incorporating the track of FIGURE 1 is to be used as a part of a gang of mutually releasing switches, the pin shown in dotted lines in FIGURE 2 is removed and another pin 5, 6 is screwed firmly into place lower down the lever 7, the head 8, 9 of the pin 56 also. serving to locate a resetting bar 13 with respect to the pin. This is shown in FIGURE 2. The portion of this pin that co-operates with the track is shown in its Oflf position at 1 in FIGURE 1.

As shown in FIGURE 2, the pin 5, 6 used has a stepped configuration. The narrow end part 5 of the pin is of smooth circular section and forms the tracking portion of the pin. The central part of the pin 6 is thicker and is threaded to enable the pin to be screwed into a tapped hole in the pin lever arm 7 until the ledge formed by a further thickened section 8 bears tightly against the lever 7 so as to secure .the pin firmly in position. The section a 8 serves for locating a resetting bar 13 and the slotted head 9 serves to hold the resetting bar in position.

On operation of the push-button against its restoring spring from the normal position shown in FIGURE 1, the pin is moved to the right as it slides along the sloping face 2. On further movement of the push-button, the pin slides off the end of the sloping face 2 along the face of ledge 4 and comes to rest against face 3. On release of the push-button, .the pin is trapped on the ledge 4- and prevents the push-button from returning to the Olf position. Repeated operations of the key have no further effect.

The pins of all the switches of the gang are attached to the common resetting bar 13 in the same manner so that the movement of one pin towards the right in sliding up the face 2 causes all pins to move the same amount in the same direction. If one push-button is operated, i.e. its pin is resting against the ledge 4, and another pushbutton is depressed, the movement of the pin of the second pushbutton up the face 2 will move the pin of the operated push-bultton over the lip of the projection 11 so that it no longer rests on the ledge 4 and its push-button can restore to its Off position under the influence of its restoring spring a The resetting bar is not provided with any additional form of guide to control its motion as it is held in place by the pins to which it is attached. It is not necessary to retain the individual lever springs on the switches they could be replaced by one or more springs acting on the resetting bar. Generally speaking, however, it is more convenient to leave the individual springs in position in order to simplify the mounting of the resetting bar.

to the V track shown in FIGURE 1 but with an addif tional release track 12 extending from the inner angle of the V towards the right-hand limb of the V to form a ledge 15 and then downwardly towards the base of the V. The ramp, which extends over the whole length of the right-hand limb of the V in FIGURE 1 is confined to the upper part of such limb above the release track 12 in FIGURE 3 to form an extension of the step 16.

When a switch incorporating the track arrangement of FIGURE 3 is used for push-on, push-off operation the V-shaped outer track functions exactly as previously described. There is no tendency for the pin to enter the additional release track 12 as its load spring urges it towards the left-hand side of the tracks during operation. To convert a row of individual push-on, push-off switches into a mutually releasing gang of switches, the pin and lever assemblies of all the switches are pulled out of their respective tracks and a common resetting bar 33 is placed between the pin levers '7 and the faces of the track members such that the pins engage in slots 17 (FIGURE 5) in the resetting bar when they are replaced in their tracks. 7 When a switch is in the On position, its pin is in contact with the ledge 15. On the operation of another switch of the gang, the resetting bar is moved to the right by the pin of the second switch moving up the right-hand side of the V track; thereby carrying the pin of the operated switch into the release track 12. The motion of the resetting bar is sufficient to ensure that the pin is carried well beyond the edge of ledge 15 so that the switch-releases. During the release of the switch, the pin descends the step 16 to regain its Off position. On re-operation of theswitch, the pin is prevented from re-entering the release track 12 by the extended face of the step 16.

By ensuring that the horizontal distance travelled by the pin .when moving along the operating track is greater than the distance which has to be travelled in order to clear the ledge 15 of the release track, the mutual release action is ensured and the shape of the slots in the resetting bar is not critical dimensionally; as are other dimensions such as the spacing between adjacent switches, etc. This is in direct contrast to the separate track arrangement shown in FIGURE 1. In the latter case, if one of the projections 11 thereon is longer than all the rest, the pin of the switch concerned will not be carried clear of the end of the projection on release of the switch by the operation of another switch, To overcome this disadvantage, the ends of the projections are rounded or angled so that the pin will be carried over the end of the projection by the force exerted by the Push-button restoring spring.

A schematic plan view of the track members of three mutually releasing switches A, B and C and the common resetting bar 13' is shown in FIGURE 5. Switch B is shown in the On position. The pins 114 in this figure are shown in the slots I7 of the resetting bar 13'. The length of the slots is such that it accommodates pins in both the operated and unoperated condition without restricting the movement of either. As may be seen from FIGURE 5, the pin of the operated switch B is at the let -hand end of its slot, and the pins of the unoperated switches A and C are at the right-hand ends of their slots. The operation of either of the two unoperated switches will cause its pin to move to the right and, in turn, cause the resetting bar I to move to the right. Movement of the resetting bar causes the pin of the operated switch B to be carried clear of the end of ledge 15. The switch is then restored to its Off position by the pushbutton restoring spring.

With this type of interlocked switch the pins do not all move in unison; so each must retain its own spring. It has been shown, however, that the changing of a row of individual switches into a row of mechanically-interlocked mutually releasing switches can readily be effected and that no modification is required to any part of the switch other than the insertion of the resetting bar under the pin,

levers of all switches. The operation may, therefore, be carried out without disconnecting or dismantling the switches.

Referring now to FIGURES 6 and 7 there are here shown an individual switch (FIGURE 6) and a gang of three mutually releasing switches (FIGURE 7). The track formations of all the switches of these FIGURES 6 and 7 are those of FIGURE 1 of the accompanying drawings and to emphasize this the right hand switch of the gang of FIGURE 7 has been shown with its pin and lever removed and the track face cut away in the same manner as the showing of FIGURE 1. It is to be understood however that the track formation is in practice in a the form indicated in dotted lines on the central switch of the gang.

"of frame 21 by means of a spring clip 22, Lamp contact springs 23 and 24 are fixed into the base of the button guide 20 and serve also to locate and retain the lamp. The lamp may be removed for inspection purposes irrespective of the position of the push-button by removing the transparent cap 18 and withdrawing the lamp through the front of the switch by means of a standard lamp extractor.

The push-button slides over the outer face of the button guide 2%) during operation and is restored to the position shown, with the push-button in contact with the upper horizontal limb of frame 201, by the action of'the helical spring 25 surrounding the button guide 2d. For individual switch operation a tracking pin 26 is attached to a pin lever 27 which is free to move in a plane perpendicular to that of the drawing about a pivot pin 28. A load spring 44 acts on the lever and pin assembly to bias the pin so that it presses in a downwards and sideways direction into a track 30 which is formed and arranged to operate in the manner described with reference to FIGURE 1.

For gang operation the pin 26 is replaced by pin 5, 8, 9 the track-engaging portion of which normally rests at the lower end of the lower track end of the lower track portion 1, 2, 4, 3 (FIGURE 1). The head portion 9 of the pin passes through a shaped aperture 45 in a gang support plate 41, to which the frame members 21 of the individual switches are attached by bolts such as 46, and through a further aperture on the resetting bar 13. The pins and resetting bar are held together by securing clips such as 43 engaging the neck between shoulder 8 and head 9 of each pin.

A springset lifting pin 31 attached to a contact lever spring 32 res-ts at a point near the bottom of a contactoperat-ing slope 33, formed on the side of the push button. When the push-button and cap assembly is pressed, it moves through a guide hole in the frame 21 and over the push button guide 20. The springset lifting pin 31 slides up the slope 33 and causes the contact 34 of spring 32 to press against the contact 35 of the spring 36.

The contact spring 32 and 36 are clamped between a clamping plate 37 and the turned-up section of the frame 21 by means of fixing screws 38, 39, and are insulated therefrom by means of insulating plates 40.

What I claim is:

In a multiple pushabutton control assembly, the combination comprising a plurality of push-button operated units arranged in essentially side-by-side relation, each said unit including a support structure actuatable longitudinally of itself, spring means biasing said support structure to a starting position, a push-button for actuating said support structure from said starting position, an essentially heart-shaped trackway provided on a side face of said support structure, said track-way also including a reset track part extending from the base of the notch portion formed between the two lobes of the heart to one of the upwardly and outwardly inclined parts of said trackway, a lever pivotally mounted adjacent to and parallel .with said trackway, a pin on said lever, spring means loading said lever and pin thereon into lateral engagement with said track-way, said pin being located at the lower end of said tnackway when said support structure occupies its starting position and being transferred to said notch portion whenever said support structure is pushed to a locked-in position, and a reset bar movable longitudinally of itself and extending across all of said support structures .of said push-button opera-ted units in a direction transverse .to the direction of movement of said support structures, said reset bar including a plurality of longitudinally spaced slots therein individual to and receiving the respective pins on said levers, each said pin being located at the same end of the slot when the appertaining support structure occupies its starting position and being relocated to the opposite end of the slot when said support structure is pushed to a locked-in position, whereby upon pushing any one of said support structures from its starting position the movement of the pin appertaining thereto along the trackway will cause said reset bar to shift longitudinally and thereby move the pin appertaining to any support structure occupying its locked-in position from said notch portion along said reset track part onto said inclined track part whereupon the biasing spring means appertaining to said support structure restores the latter to its starting position.

References Cited by the Examiner UNITED STATES PATENTS 2,592,660 4/52 Crumley 200159 2,671,354 3/54 Goos 200-160 2,793,257 5/57 Hu-tt 200153.12 2,831,075 4/58 Durnke et al. 280-503 2,874,244 2/59 Hamblett et al ZOO-153.11 2,933,945 4/ Brewster et .al. 2,933,948 4/60 Thompson. 2,946,237 7/60 Herbert. 2,956,446 10/ 60 Ensign et al. 200- 2,996,593 8/61 McMains 20016O 3,071,658 1/63 Demarest 200153.11

FOREIGN PATENTS 1,212,545 3/60 France.

924, 107 2/55 Germany. 1,088,586 9/60 Germany.

BROUGHTON G. DURHAM, Primary Examiner. 

